DIFFERING INFECTION PATTERNS OF DENGUE AND YELLOW-FEVER VIRUSES IN A HUMAN HEPATOMA-CELL LINE

Dengue (DEN) and yellow fever (YF) viruses are responsible for human d iseases with symptoms ranging from mild fever to hepatitis and/or hemo rrhages. Whereas DEN virus typically induces only limited foci of necr osis in the liver, YF virus infection is characterized by devastating lesions, In a human hepatoma cell line (HepG2), the kinetics of DEN an d YF virus replication and release from the cells and the nature of ho st cell response to viral infection were compared, DEN virus infection was characterized by the early appearance of intracellular viral anti gens, major ultrastructural cytopathic changes as early as 32 h after infection, extensive apoptotic cell death, and a low production of inf ectious particles. In contrast, YF virus grew exponentially to high ti ters and induced cytopathic changes only 72 h after infection. Differe nces between the infection processes of the two viruses observed in th e hepatoma cell line may explain the different liver pathologies.